A a think encrusted layer of fecal particles that has dried and hardened and somewhat fused with the skin of the buttocks. It results from smearing butt excrement when whiping rather than actually removing it. As it hardens it becomes brittle and starts to crack, then small particles of the fecal-layer waft into the air and can get lodged in people's nostrils or open wounds, causing severe irritation, runny noses and gagging.

Man, Mandy is such a slut. I was gonna do her doggy style but her whole butt was encrusted with buttflakes.

Man, I went to a gay bar last night but i couldn't breathe cuz the air had a visible mist of brown buttflakes.

A thick encrusted layer of fecal particles that has dried and hardened and somewhat fused with the skin of the buttocks. It results from smearing butt excrement when whiping rather than actually removing it. As it hardens it becomes brittle and starts to crack, then small particles of the fecal-layer waft into the air and can get lodged in people's nostrils or open wounds, causing severe irritation, runny noses and gagging.

Man, Mandy is such trailer trash. I did her doggy style even though her whole butt was encrusted with buttflakes. Each thrust i drilled into her shook off more buttflakes, creating a thick green mist of butt flakes, and I gagged.

Those who have it, despise it. Those lacking it, desire it. This paradox that has, for many years, consumed our nation, is none other than BUTTFLAKES. What are buttflakes, you ask?
Historians have traced this common characteristic back to the early days of equestrian training. Horse riders, after a long day of arduous training, have been shocked to find none other than peeling, dried skin on their buttocks. Common side effects are a sporadic snap, crackle and pop of the buttocks upon impact with jeans, and other such materials. Scientists have come to identify this characteristic as butt dandruff, or as modern day society has deemed it, BUTTFLAKES.

person #1: "Wow, my butt feels sore." *peels off layer of clothing* "What is this? My butt has more cracks than the San Andreas fault!"
person #2: "Oh you silly thing, you have BUTTFLAKES! DUH!"